Royals director of football Nick Hammond said: "Michael is a very experienced centre-half who has played at the highest level, including nearly 150 Premiership appearances and a European final.

"This season he has captained a Stoke team which has the best defensive record in the Championship, and we think this is a very sensible signing which gives us additional quality as we enter the final stages of the season."

Chairman John Madejski added: "I'd like to welcome Michael to Reading. He is a high calibre performer who has been in excellent form this season and will add experience to our squad.

"This completes a busy period of activity for us in the transfer window and we are very satisfied with the deals we have secured."